Patent GB-827780-A (GB)
Title: Gas turbine power plant
IPC: F02C7/32
Filed: 1957-05-20
Abstract: 827,780. Gas turbine plant. STANDARD MOTOR CO. Ltd., and HAMBLING, S. K. Feb. 26, 1958 [May 20, 1957], No. 15888/57. Class 110(3). A gas turbine plant has auxiliaries which, during acceleration and idling of the plant, are arranged to be driven by an electric motorgenerator, functioning as a motor, and which, during normal conditions of operation of the plant, are arranged to be driven by an air turbine which is supplied with working fluid from a compressor of the plant and which is connected to drive the auxiliaries through reduction gearing and to drive the motor generator through a one-way driving device when the motor-generator functions as an electrical generator. A gas turbine plant, comprising a compressor 1 supplying combustion air to a combustion chamber 3 feeding a turbine 2 driving the compressor 1 and an independent useful output power turbine 4, has air bled from the discharge of the compressor 1 and supplied, through an intercooler 7 and valve means 15, to an air turbine 6. The valve means 15 is operated by the accelerator pedal 17 through a control device 16. The air turbine drives a motor generator 11 through a reduction gear 9 and a free-wheel or other one-way driving device 10. The motor generator 11 has a shaft 12 for driving a fuel pump 13 and a lubricating pump 14. The arrangement is such that during acceleration and idling of the turbine 2 and compressor 1, the motor generator 11 is connected to a battery 18 and functioning as a motor drives the pumps 13, 14. The device 10 allows this to be done without rotation of the reduction gear and air turbine. During normal running air is supplied from the compressor 1 to the turbine 6 which drives through the reduction gear 9 and device 10 the motor-generator 11, which functions as a generator, and the pumps 13, 14. Auxiliaries other than pumps may be driven in this manner. The intercooler 7 may be cooled by air sucked in by the compressor 1 or by air forced through the intercooler by a blower. The air discharged from the turbine 6 may be discharged to atmosphere or may be used to condition the atmosphere in a vehicle equipped with the power plant or in a living space. The control device 16 and valve means 15 are shown in detail in Fig. 2. The valve means 15 includes a valve 19, in the ducting between the compressor 1 and air turbine 16, which is mounted on a rod 20 connected to the contact plate 22 of a switch 21 for changing the motor-generator circuit from a motor to a generator circuit and vice versa. The rod 20 passes through solenoids 23, 24 which when energized move the rod to close the valve 19 and to change the motor-generator circuit from the generator to the motor circuit. As shown, the solenoids are not energized, valve 19 is then open so that air is supplied to the air turbine 6 and the motor generator functions as a generator. If the accelerator pedal 17 is depressed quickly, the piston 31 will close the switch 27 against the action of the spring 32. The solenoid 24 will then be energized and valve 19 closed and the motor generator will act as a motor. The solenoid 23 which is connected through a short-interval time switch 34 and the motor switch 21 to the battery 18 will also be energized and will hold the valve 19 closed until the switch 34 has opened or until the compressor discharge pressure acting on the valve 19 overcomes the solenoid 23. The switch 27 is opened by the spring 32 after a given interval due to the leak through the bleed orifice 30. This orifice also prevents operation of the switch 27 when the pedal 17 is operated slowly.